Concrete placing apparatus



' Dec. 22, 1942. JACKSON A 2,306,124

w 1 x I) I] CONCRETE PLACING APPARATUS Filed April 28, 1941 INVEANTOR. def/47.61 l-ffmzsm fl I ATTORNEYS.

Patented Dec. 22, 1942 UNETED STATES PAT-NT orrlce 2,306,124 CONCRETE PLACING APPARATUS Corwill Jackson, Ludington, Mich.

Application April 28, 1941, Serial No. 390,769

7 Claims. (01. 94--48) This invention relates to improvements in concrete placing apparatus.

The main objects of this invention are:

First, to provide an improved machine for laying pavements and other concrete slabs or surfaces which is well adapted for the placement of dry or harsh mixtures or mixtures having low Water content and with aggregate such as crushed stone.

Second, to provide a machine of this character which is effective for uniform distribution and uniform working of the concrete material treated across the slab being laid.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

Preferred embodiments of the invention are illustrated in the accompanying drawing, in

which: 7

Fig. 1 is a fragmentary view partially in side elevation and partially in vertical section on line Il of Fig. 2 of a concrete working or paving machine embodying the features of my invention. Fig. 2 is a fragmentary front elevation of the screed. I

Fig. 3 is an enlarged fragmentary horizontal section through the front plate of the screed on line 33 of Fig. 2.

Fig. 4 is a fragmentary front elevation of a modified form or embodiment of my invention.

Fig. 5 is a vertical section through the screed on a line corresponding to line 5-5 of Fig. 4.

Fig. 6 is a fragmentary horizontal section on line 6-6 of Fig. 4, arrows indicating in a general way the direction of the vibratory impulses to the concrete mass being treated.

My present invention relates to the general type of paving machine illustrated in my Patent 2,219,246, issued October 22, 1940, and is an adaptation and improvement upon the invention of that patent which discloses a screed or shoe mounted for horizontal reciprooatory movement as it is advanced and having a front plate adapted to support a substantial mass of concrete as the shoe is advanced in a horizontal plane, and means for vibrating the front plate at high frequency. My present invention substantially increases the capacity of the machine of said patent and is effective in preventing aggregate such as crushed stone from becoming interlocked and wedged together, aiding very materially in distributing the mass across the slab being laid and very effectively vibrates the harsh or dry mixtures or mixtures of low water content, converting the same to a placement condition.

In the accompanying drawing, I represents one of the side forms for the concrete to be placed. It will be understood that there is one of these at each side of the slab to be placed. These forms constitute rails or tracks for the paving machine carriage 2 which is provided with wheels 3 traveling on the forms.

The screed 4 is preferably mounted for horizontal reciprocating movement transversely of the path of travel of the screed, being reciprocated by the pitman connecting rod 5 connected to a suitable crank 5 and to a pitman pin on the rear side of the screed. Thrust rollers 1 advance the screed as the carriage is advanced. I have not illustrated the means for raising and lowering the screed or the means for driving the crank 6 as these parts form no part of my present invention.

The screed is provided with a shoe or bottom 8 and a front plate 9, the front plate having at its lower end a forwardly projecting inclined strikeofi blade 10.

The connections for the various parts of the screed are not illustrated but it will be understood that they are suitably connected to withstand the vibrations of one or more vibrating units l l which are mounted within the screed, the mounting being preferably connected both to the bottom of the shoe and face plate. These vibrating units, in the structure illustrated, are electric motors having rotors l2 provided with unbalancing weights I3. The axis of the rotor is arranged parallel with the screed and the vibrating means is such as to vibrate the screed at high frequency in the order of 3600 revolutions per minute and sometimes exceeding that. The amplitude of the vibrations is not relatively great.

The screed is provided with forwardly projecting wings M at the ends thereof which ride upon the rails. The screed is adapted to support a substantial mass of concrete material l5 being worked as shown in Fig. 1. The lower or concrete supporting portion 16 has vertical corrugations or fiutings ll, these vertical corrugations or fiutings being of substantial transverse dimensions. These are preferably formed in a separate plate I8 secured to the main face plate of the screed by bolts 19 engaged in the vertical slots 20.

The plate I8 is preferably upwardly and rearwardly inclined and has a flange 2| on its lower edge resting on the strike-ofi blade so that this plate constitutes in effect an extension for the strike-off blade.

In the embodiment shown in Figs. 4, 5 and 6,

the flutings or corrugations 22 are gradually curved instead of being abruptly curved as best shown in Fig. 3. In this embodiment, the fluted plate 23 is attached to the face plate 24 of the screed 25 to rest directly against the same and conform to fit the same. These corrugations or flutings of the face of the screed substantially increase the surface thereof and also provide axially disposed surfaces as indicated by the arrows in Fig. 6 which impart vibrations to the material treated in a plurality of directions. With the axis of the vibratory means arranged parallel with the screed, the whole screed is vibrated in a plane parallel with the path of advancement of the screed while the angularly disposed surfaces set up intersecting vibrations.

The alternating raised and lowered portions aid very substantially in the distribution of the material across the slab and they effectively break up or displace aggregations or collections of aggregate.

I have illustrated and described my improvements in embodiments which I consider very desirable. It will be understood that I have not attempted to illustrate the parts in relative proportions but it is believed that the disclosure made will enable those skilled in the art to embody or adapt my improvements as may be desired.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a machine of the class described, the combination of a carriage, a screed mounted for forward advancement and. reciprocating movement transversely of the path of forward travel, said screed having a front plate provided with a vertically fluted face portion of substantial vertical height adapted to rearwardly sustain and advance a substantial mass of material treated. as the screed is advanced, the flutes extending a substantial distance vertically above the lowermost edge of the front surface of said plate and providing a plurality of vertically elongated vibratory surfaces disposed angularly relative to each other and of substantial dimensions so as to receive substantial amounts of material to be treated forwardly of the screed, means for reciprocating said screed as the carriage is advanced, and means for vibrating the front plate of said screed at high frequency.

2. In a machine of the class described, the combination of a carriage, a screed mounted on said carriage for forward advancement and reciprocating movement transversely of the path of forward travel, said screed having a shoe and a front plate provided with a vertically fluted face portion of substantial vertical height adapted to rearwardly sustain and advance a substantial mass of material treated as the screed is advanced, the flutes extending a substantial distance vertically above the lowermost edge of the front surface of said plate and providing a plurality of vertically elongated vibratory surfaces disposed angularly relative to each other and of substantial dimensions so as to receive substantial amounts of material to be treated forwardly of the screed, means for reciprocating said screed as the carriage is advanced, and means for vibrating the front plate of said screed at high frequency.

3. In a machine of the class described, the

combination of a carriage, a screed mounted on said carriage for forward advancement, said screed having a shoe and a front plate provided with a vertically fluted face portion of substantial vertical height adapted to rearwardly sustain and advance a substantial mass of material treated as the screed is advanced, the flutes extending a substantial distance vertically above the lowermost edge of the front surface of said plate and providing a plurality of vertically elongated vibratory surfaces disposed angularly relative to each other and of substantial dimensions so as to receive substantial amounts of material to be treated forwardly of the screed, means for reciprocating said screed as the carriage is advanced, and means for vibrating the front plate of said screed at high frequency.

4. In a machine of the class described, the combination of a screed adapted for forward advancement and reciprocating movement transversely of the path of forward travel, said screed having a plurality of vertically disposed, vertically elongated and angularly associated surfaces extending substantially above the lower edge of the front of said screed and adapted to rearwardly sustain and advance a substantial mass of material treated as the screed is advanced, means for reciprocating said screed as the carriage is advanced, and means for vibrating said screed and its front plate at high frequency including an unbalanced rotor mounted on the screed with its axis longitudinally of the screed whereby the vibrations transmitted to the material from said angularly disposed surfaces are transmitted in a plurality of directions.

5. In a machine of the class described, the combination of a screed'having a plurality of vertically disposed, vertically elongated and angularly associated surfaces extending substantially above the lower edge of the front of said screed and adapted to rearwardly sustain and advance a substantial mass of material treated as the screed is advanced, and means for vibrating said screed and its front plate at high frequency whereby the vibrations transmitted to the material from said angularly disposed surfaces are transmit ed in a plurality of directions.

6. In a machine of the class described, the combination of a screed adapted for forward advancement and reciprocating movement transversely of the path of forward travel and having a front face comprising a plurality of vertically disposed, vertically elongated and angularly associated surfaces extending vertically substantially above the lower forward edge of said face and adapted to rearwardly sustain and advance a substantial mass of material treated as the screed is advanced, means for reciprocating said screed as it is advanced, and means for vibrating the front face of the screed at hi h frequency.

'7Iin a rnachine of the class described, the combination of a screed and having a front face comprising a plurality of vertically disposed, vertically elongated and angularly associated surfaces extending vertically substantially above the lower forward edge of said face and adapted to rearwardly sustain and advance a substantial mass of material treated as the screed isadvanced, and means for vibrating the front face of the screed at high frequency.

' CORWILL JACKSON. 

